Incunabula Cataloguing Project. 5: An early astronomical calendar and an innovation in book design

The book featured here, a short publication of 64 pages, is a notable one in the history of printed books. It has the distinction of being the first book to have a separate title page, with the (in verse) title, author’s name, place of publication, imprint date given in Arabic rather than Roman numerals, the names of the printers, plus a decorative woodcut border. It is also the first Italian book to feature extensive use of woodcut initials. (Figure 1)

The title page was an innovation in book design. The early printers sometimes, but not always, followed the medieval manuscript tradition of naming the title of the work, the author, and details such as who made it, where and when, at the end of the book in the colophon. Standard features of books such as title pages and page numbers did not come into common use until the early 16th century, 50-plus years after the invention of printing.

This book is the second Latin edition of a work on astronomy known as the Kalendarium, written by Johannes Regiomontanus. It was printed in Venice in 1476 by three German printers: Erhard Ratdolt, of Augsburg, Bernhard Maler, also of Augsburg, and Peter Löslein, of Lagenzenn, in Bavaria.

Johann Müller (1436-1476) is better known by the Latinised version of his name, Johannes Regiomontanus, which was derived from Regio Monte, the Latin name of his place of birth Königsberg (literally “King’s mountain”), in Bavaria, Germany. A renowned astronomer, mathematician, and instrument maker, Regiomontanus travelled widely in Europe. Realising the potential of the new technology of printing to spread scientific knowledge, he set up a printing press in Nuremberg in 1472 and was the first person to print mathematical and astronomical works, including his own Kalendarium, which first appeared in 1474.

The Kalendarium was the first work to apply modern scientific methods of astronomical calculation and observation to the problems of the Julian calendar and to the accurate prediction of eclipses. It was, as the name suggests, an astronomical calendar. For each month of the year there is astronomical data for the years 1475, 1494 and 1513, alongside an almanac which includes the days of the chief fasts and feasts, the principal festivals being printed in red (from which we derive our saying “red letter day”), the path of the sun through the signs of the zodiac, and the times of the new and full moons in hours and minutes. (Figure 2)

After the almanac comes a sequence of sixty woodcuts predicting the times and durations of solar and lunar eclipses for the years from 1475 to 1530. The woodcuts show the extent of obscuration of the sun and moon, the occluded parts are printed in black and the unobscured parts are hand-coloured in yellow. (Figure 3)

There are also four paper instruments printed on four pages glued together back-to-back. One of these instruments is entitled Instrumentum veri motus lunae (Figure 4) and consists of two woodcut volvelles, or moveable paper wheels, held to the page by a piece of string through their middle. These can be turned to show the motion of the moon, enabling the reader to locate the position and phase of the moon according to date and time.

Another instrument entitled Quadratum horarium generale (Figure 5) has an articulated brass pointer and was used to calculate the hour (a portable sundial). Of the other two instruments, one was used for calculating unequal hours, and the other, a quadrant, was used for telling the time of day by measuring the sun’s altitude.

There is much else packed into the book, including tables of golden numbers, of moveable feasts, of astrological co-ordinates, of corrections for telling the time in different locations, charts for the length of daylight hours for each day, seasonal locations of the sun in the sky, phases of the moon, conversions of planetary hours, and an observation that longitude at sea could be determined by calculating lunar distances. It ends with a discussion on the errors in calculations of Easter, along with a table calculating the true date of Easter for the years from 1477 to 1531.

The Kalendarium was a very popular book. It was first published in 1474 and a further 13 editions in Latin, German and Italian had been printed by 1499. Printed (mass-produced) calendars and almanacs were widely read in Europe and allowed ordinary people with little specialist knowledge to plan their daily lives.

This copy of the book in the John Rylands Library is part of the extensive collection of early printed books belonging to George John Spencer, 2nd Earl Spencer (1758-1834). Spencer was the one of the foremost book collectors of his day and he put together what is probably the most important private library in Europe. He acquired this copy of the Kalendarium in Vienna in 1817, at the sale of the Apponyi Library (Bibliotheca Apponiana). Count Anton Georg (Antal György) Apponyi (1751-1817), a Hungarian politician and patron of the composers Haydn and Mozart, assembled the Apponyi Library in Vienna. Following his death in 1817 part of the library was sold by his son Anton Apponyi (1782-1852).

The full catalogue record of the John Rylands Library copy can be viewed here.